The footage records the man walking from the western side of the park, where Mr O'Shea's body was found, to the north-east corner of the park, then east along Toorak Road to Como Avenue, where he turned left and walked towards Como Park.

Detective Inspector Andrew Stamper of the homicide squad appealed for public help to identify the man.

"This is a particularly horrendous murder which occurred in one of Melbourne's most favourite parks," he said.

"Someone out there knows exactly who this man is. They know who he is, why he was there, and what connection he has to our victim.